Instead of using any robust system for astrology you could maybe focus on the hours of the seven "planets" (Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon), in this order. It's very very traditional on middle ages, renaissance, and early modern "occult philosphy".

Instead of hours you could base it on the 7 days (very traditional too) or even on the 12 months (each connected with one greek/roman god - that's somewhat traditional too, but obviously more connected with the pagan world).

Devs, let me know if you need some help with traditional astrology knowledge OR historic knowledge about how people did view astrology.

BUT PLEASE DON'T PUT MODERN ASTROLOGY INTO THE GAME (uranus, pluto, solar sign only, horoscope based only on planets positions...)